Okay... so I finally pawned my few guppies in my mid sized tank over to my mom... so my adf's will go in another tank...
NOW I need to know what kind of substrate to get for a dwarf puffer... should I keep my gravel since it already has bacteria in it and the tank is good and super cycled? I am planning to decorate it w/ tons of plants and hiding places for my little guy when I get him since I have read that they like a lot to view and explore....
any advice on water parameters from experience

I am also thinking of breeding... .any advice
I also read they get along w/ oto catfish is this true? I was going to get one to "housekeep"...
I know I have to keep him up in snails for his teeth, and they love to eat them... and what foods they like....